J. Org. Chem. 1993,58, 7310-7312
7310
Synthesis of lH-l-(1-Alkyny1)-6methyl-l,2,3-benziodoxathiole3,3-Dioxides: Alkynyl(ary1)iodoniumSulfonates with Heterocyclic Iodine
Table I. 1-AlkynylbenziodoxathioleDioxides 6 from Reactions of 4 with Terminal Alkynes
molar ratio compound Sa
Gerald F. Koser,' Guoping Sun, Cyndi W.Porter, and Wiley J. Youngs
Sb
Department of Chemistry, The University of Akron, Akron, Ohio 44325-3601
5e
n-C& n-CeHu i-Bu
Sd
S-BU t-Bu
Sf 5g
Sh si
Prior to 1981, alkynyl(qheny1)iodoniumcompounds 1 were little more than structural curiosities, only two exampleshaving been reported in the chemicalliterature.'$ The subsequent development of methods for the synthesis of alkynyl(pheny1)iodoniumtoaylates? tetrafluoroborates:' and triflates6 (Le., X-= TsO-, BF4-, CF3SOs) has since stimulated considerable interest in the reactivity and synthetic utility of this class of iodonium ~ a l t a . ~ ~ ~ The first tosylate compounds were prepared by the treatment of terminal alkynes, RCECH, with [hydroxy(~sy1oxy)iodol bekene (2, HTIB),&sbtypically in CHC13 at reflux?b However, this approach is restricted to alkynes with aryl or bulky alkyl gr0ups,3~1~ and when R was n-Pr, n-Bu, n-C6H11, [@-(tosyloxy)vinyll (pheny1)iodonium tosylates 3 were obtained instead.3b The incorporation of
n-Pr
n-Bu
so
Received August 6,1993
R
cyclohexyl
Ph
talkvne14) 511 5/ 1 31 1 511 5/ 1 2.511 511 1.811 511
isolated vield ( 7% 61 54
41 51 66 32 70 26 51
the resulting solutions a t 0 OC with aqueous Na0Ts.h In this way, tosylate salts of 1 with R = Me, Et, n-Pr, and n-Bu have been obtained in 62-89??, yields. We now report the use of lH-l-hydroxy-5-methy1-1,2,3benziodoxathiole 3,3-dioxide(4), a cyclic analog of HTIB, for the direct synthesis of alkynyl(ary1)iodonium arenesulfonates from terminal alkynes; eq 1. The products are lH-l-(l-alkynyl)-5-methyl-1,2,3-benziodoxathiole 3,3-dioxides 5;8 more significantly, congeners of 5 with linear alkyl groups in the alkynyliodonio moiety can be readily obtained without the use of a desiccant or silyl activation of the alkyne The hydroxy sulfonyloxy iodane 4 is less reactive than h JIB toward terminalalkynes, and it proved expedient to facilitate the reactions shown in qq 1 with p-toluenesulfonic acid.
OTs
X-
R-CEC-Y-Ph,
I
i-
OH 2
1
OH 4
R
\ C=CH-y-P /
''7 IPI R
h, -0Ts
TsO
3
linear alkyl groups into 1 (X- = TsO-) was first achieved by the treatment of propyne and 1-hexyne with HTIB (CH2C12, rt) in the presence of a silica bead desiccant, but the yields (19%, 12%) were lowsSd A much better procedure, based on the standard approach to tetrafluoroborate salts,& entails the BF3-EtzO-induced coupling of (trimethylsilyl)alkynes, RCWSiMe3, with iodosobenzene, PhI=O (CHCl3, rt), and subsequent treatment of (1) Beringer, F. M.; Galton, S. A. J. Org. Chem. 1965,30,1930.
(2)Merkushev, E.B.; Karpitekaya, L. G.; Novosel'taeva, G. I. Dokl. Akad. Nauk. SSSR 1979,245,607. (3) (a) Koaer, G. F.; Rebrovic, L.; Wettach, R. H.J. Org. Chem. 1981, 46,4324.(b) Rebrovic, L.;Koser, G. F. J. Org. Chem. 1984,49,4700.(c) Stang, P. J.; Surber, B. W. J. Am. Chem. SOC. 198S,107,1452.(d) Stang, P. J.; Surber, B. W.; Chen, ZC.; Roberta,K. A.; Anderson, A. G. J.Am. Chem. SOC. 1987,109,228.( e ) Kitamura, T.; Stang, P. J. J. Org. Chem. 1988,53,4105. (4)(a) Ochiai, M.; Kunishima, ha.; Sumi, K.; Nagao, Y.; Fujita, E. Tetrahedron Lett. 198S,26,4501.(b) Ochiai, M.; Ito, T.; Takaoka, Y.; Maaaki, Y.; Kunishima, M.; Tani, S.; Nagao, Y.J. Chem. SOC.Chem. Commun. 1990,118. (5) (a) Stang, P. J.; Arif, A. M.; Crittell, C. M. Angew. Chem. Znt. Ed. Engl. 1990,29,287.(b) Stang, P. J.; W i l l i i o n , B. L.; Zhdankin, V. V. J. Am. Chem. SOC.1991,113,5870. (c) Wilhamson, B. L.; Stang, P. J.; Arif, A. M. J. Am. Chem. SOC.1993,115,2590. (6)(a) Stang, P. J. Angew. Chem. Int. Ed. Engl. 1992,31,274(Review). (b)Varvoglis,A. The Organic Chemistry ofPolycoordinutedIodine;VCH Publishers: New York, New York, 1992;pp 207-277. (7)Lodaya, J. S.;Koeer, G. F. J. Org. Chem. 1990,55,1513.
In a typical experiment, a mixture of 4 (5.W1mmol), p-TsOH.Hz0 (5.0 mmol), and 1-hexyne (25.0 mbol) in MeCN (40 mL) was heated under reflux for 20 h. The resulting solution was then concentrated, and the oil that remained was washed (in CHCls) with 5 % NaHCO3 and H2O to remove toluenesulfonic acid. The solid, thus obtained, was recrystallized from a mixture of CH2C12, EhO, and hexanestogive lH-l-(l-hexynyl)-5-methyl-1,2,3benziodoxathiole 3,3-dioxide (5b)in 54 % yield. Similar treatment of eight other terminal alkynes with 4 gave the alkynylbenziodoxathiole dioxides shown in Table I, all of which were characterized by IR, NMR (1H, 13C), and elemental (C,H) analysis. The yields reported in Table I are those of the isolated, analytically pure compounds and appear to be regulated, at least to some extent, by the starting alkyne/4 molar ratios. The hydroxybenziodoxathiole 4 v 3s prepared from 2-amino-5-methylbenzenesulfonicacid by diazotization (NaN02, HCl), iodination (NaI, H20, A), and oxidation (355% MeC03H) and was initially characterized by NMR (8)Three l-alkynyl-1,2-benziodoxol-3(l~-ones, cyclic carboxylate
analogsof 5, have recently been prepared from l-hydroly-1,2-benziodoxol-
3(m-onc; Bee Ochiai, M.; M d i , Y.; Shiro, M. J. Org. Chem. 1991,56, 5511
-I--.
(9) 1H-l-Hydroxy-1,2,3-bemiodoxathiole 3,3-dioxideis known;see (a) Willgerodt, C . Die Organischen Verbindungen mit Mehrwertigem Jod, F. Enke: Stuttgart, 1914;p 166 (sodium salt reportad). (b) Wettach, R. H.,Ph.D. dieeertation, The University of Akron, 1981, pp 156-167 (monohydrate described).
0022-3263/93/1958-7310$04.00/0 0 1993 American Chemical Society
J. Org. Chem., Vol. 58,No. 25, 1993 7311
Notes
of the three sulfur-oxygen bond distances (1.406-1.440
A). However, the iodine-sulfonate linkage in 4 is 0.1 A
shorter than it is in HTIB (2.473 A).12 Compound 4 is insoluble in MeCN, even at reflux, and it seems likely that the “catalytic” action of p-TsOH is due to the protonation of 4 at the sulfonate ligand to give 6. Indeed, when 4 was treated with TsOH.Hz0 in MeCN
OTs OH
6
at reflux, the iodane “dissolved”. However, when the solution was allowed to cool, only 4 separated and was recovered in 94% yield. Experimental Section
Figure 1. Thermal ellipsoid projection of 4. Table 11. Selected Bond Distances and Angles for la-l-Hydroxy-5-methyl-1J,3-benziodoxathiole 3,3-Dioxide (4)‘ bond distance (A) bond angle (deg) ~~
~
~
2.372(5) 0(1)-1-0(4) 168.6(2) 1.933(5) 0(4)-1-C(1) 92.3(2) 1.440(5) O(l)-I-C(l) 76.9(2) 1.406(6) 1-0(4)-H 98.7(1) 1.415(9) 0(1)-S-0(2) 113.4(4) 1.010 0(1)-S-0(3) 110.0(4) 2.125(6) 0(2)-S-0(3) 114.0(4) 1.759(6) 0 The numbering scheme in Table I1 refers to the thermal ellipsoid projection shown in Figure 1 and not to the numbering scheme employed to name compound 4.
(IH, 13C) and elemental (C,H) a n a l y s i ~ .In ~ order to ascertain the influence of planar, cyclic vs nonplanar acyclic structures on the asymmetric [3c-4el hypervalent bondlo of hydroxy sulfonyloxy iodanes, a single crystal X-ray structure of 4 was also determined.llaIb As expected for a X3-iodane, molecules of 4 (Figure 1, Table 11) are approximately T-shaped about the iodine atom, although the O-I-O triad in 4 (bond angle, 168.6’) is “less linear” than the O-I-O triad in HTIB (178.80).12 The I-OH bond distances in 4 (1.933 A) and HTIB (1.940 A)12are nearly the same and a bit shorter than the computed covalent distance of 1.99 A for an 1-0 single bond. The 1-0 bond to the sulfonate ligand in 4 (2.372 A) is elongated by 0.38 A and appears to be endowed with ionic character, a conclusion which is corroborated by the near equivalence (IO)See Kwer, G.F. In The Chemistry of the Functional Groups, Supplement D Patai, S.; Rappoport, Z.,Us.; Wiley: Chichester, 1983;
Chapter 18, pp 729-740 and references cited therein. (11)(a) Compound 4 (colorless parallelepiped, 0.4 x 0.5 x 0.7 mm) crystallized in the monoclinic space group P21/n: a = 5.064(1) A, b = 11.972(2) A, c = 15.493(3) A, @ = 94.88(3)’, u 935.9(3) As, Z 4, Dc 2.229g/cmS; p = 3.576 mm-l, F(O00) = 600. A totalof 1640reflectionswere recorded at room temperature on a Syntex P21 diffractometer wing Mo Ka radiation (A 0.71073A) in the ran e 3.5O d 2 8 5 4 5 O . All calculations were performed usingSHELXTLPLUQ(PCversion).The fmalagreement indices are R 4.881% and R, = 8.67% for 125 refined parameters and 1134unique obaerved reflections. (b)The authors have deposited atomic coordinates for this structurewith the Cambridge CrystallographicData Centre. The coordinates can be obtained, on request, from the Director, Cambridge Crystallographic Data Centre, 12 Union Road, Cambridge,
--
CB2 lEZ, UK.
General. The NMR spectra reported herein were recorded at resonance frequencibs of 300 (‘H) and 75 (W) MHz. ‘H Chemical shifts are ex reseed relative to residual protonated solvent in CDClS (6 7.2q and DMSO-& (6 2.49) and to DSS (6 0.00) in D2O. Couplinq constants are reported in hertz. lsC chemical shifts are expressed relative to CDCls (6 77.0), DMSOde (6 39.5), and DSS (6 0.00) in DzO. FTIR samples were thin CHzClz films;C=C maxipa were estimated (ca. f 5 cm-I) relative to polystyrene at 1601 em-’. Melting points are uncorrected. Elemental analyses were performed by Midwest Microlab, Indianapolis, IN. The sypthetic procedure for lH-l-(l-hexynyl)B-methyl-l,2,3-benziodoxathiole 3,3-dioxide(5b) is given in detail and serves as a general example. Abbreviated procedures for the remaining compounds of this series are presented. The ‘H NMR spectra bf 5a-h exhibit three multiplets in the aromatic region: 6 7.43-7.46, 6 7.83-7.90 (d, J = 8.5(5)-8.7(3) Hz), 6 7.95-8.00. The high-field and low-field aromatic multiplets of 5b and 5d-h closely resemble a doublet of doublets (J 8.48.9 Hz, 1.8-2.2 Hz) and a doublet (J 1.5-2.0 Hz), respectively, typically with a hint of kine structure that complicates the estimation of coupling constants. For Sa and 512,these multiplets more nearly resemble a ddg (high field) and a dd (low field), the additional splitting being less than 1 Hz. Sodium 2-Iodo-5-methylbenzenesulfonate.A solution of NaNOz (18 g, 0.26 mol) in HzO (40 mL) was added dropwise to a stirred, cold (0-5 “C) mixture of 2-amino-5-methylbenzenesulfonic acid (46.80 g, 250 mmol) in concd HCl (63 mL). The resulting mixture was stirred and kept at 0-5 OC for at least 30 min and was then treated with urea (ca. 0.5 g). A solution of NaI (39 g, 0.26 mol) in H20 (40 mL) was then added slowly to the stirred, co!d mixture. After the addition was complete, stirring was continued while the reaction mixture was kept for 2 h at 0-5 OC, 1h at rt, and 13 h at ca. 50 OC (i.e., until N2 evolution had nearly ceased). The mixture was then refrigerated, and the insoluble solid component was isolated and washed with MeCN. This material (peach-colored) was treated with boiling EtOH (some MeOH and EtQOthen added) and, after the mixture was allowed to cool, the insoluble solid was isolated, washed with EtOH and EtQ0,and identified as the monohydrate of the title compound (grayish-white powder, 47.6 g). Concentration of the aqueous filtrate from the firat filtration, extraction of the residual solid with MeOH, and concentration of the MeOH extract gave 17 g more of product: combined yield, 64.6 g (76%); mp > 380 OC dec; ‘H NMR (D20, DSS) 6 2.30 (8, 3 H), 7.01 (dd, 8.0,2.2 Hz, 1H), 7.83 (d, 2.1 Hz, 1H), 7.92 (d, 8.0 Hz, 1H); “C NMR (D20, DSS) 622.8,89.4,131.6(5),135.9,141.9,144.5,147.1. Anal. Calcd for C,H6INaO&H20: C, 24.87; H, 2.38. Found C, 24.33; H, 2.57. 2-Iodo-5-methylbenzengsulfonic Acid. H20 was added slawly to a stirred mixture #ofsodium 2-iodo-&methylbenzenesulfonate monohydrate (18.10 g, 53.5 mmol) in concd HCl (ca.
-
-
(12) Koser, G.F.; Wettach,’R. H.; Troup, J. M.; Frenz, B. A. J . Org. Chem. 1976,41, 3609.
7312 J. Org. Chem., Vol. 58, No.25, 1993 140mL)until a homogeneoussolutionwas obtained. More concd HCl(30 mL) was added, and the solution was stirred for 3 h at rt (cloudy), 2 h at ca. 50 OC, and overnight at rt. The cloudy mixture was then concentrated in U ~ C U Oat 5040 OC. The solid that remained wae treated with hot MeCN (2 X 30 mL),and the mixture was fiitered to give 3.30 g of NaCl (mostly). Treatment of the fiitrate with Et0 and hexanes led to the recovery of 0.8g (4% ) of the unprotonatd sodium areneeulfonate. Concentration of the second fiitrate gave an oil which graduall.7 solidified. This material wae treated with CHCb (10 mL) ana hexanes. The mixture was kept overnight at rt and filtered to give a white solid which was washed with hexanes and identified as the dihydrate of the title compound yield, 11.62 g (65% ); mp 112-114 "C; lH N M R (DzO, DSS) 6 2.30 (s,3 HI, 7.01 (m, 1HI, 7.83 ('d", 2.1 Hz, 1H), 7.92 (d, 8.0 Hz, 1H); 'SC NMR (D20, DSS) 6 22.8, 89.4, 131.7, 135.9, 141.9, 144.5, 147.1. And. Calcd for C7H,IOaS*2H20 C, 25.16; H, 3.32. Found C, 24.86; H, 3.03. The 1H and 'Bc NMR spectra (D2O) of the sulfonic acid and its sodium ealt are virtually identical. 1H-1-Hydroxy-5-methyl-1,2,3-benziodoxathiole 3,3-Dioxide (4). Peroxyaceticacid ( 3 5 %58 ~ ~mL) was added dropwise to a stirred mixture of 2-iodo-5-methylbenzenssulfonicacid dihydrate (25.05 g, 75.0 "01) in glacial aceticacid (70 mL) maintained at 1+15 OC; a clear solution initially resulted. The reaction mixture was stirred for 1h at 15 OC and overnight at rt. A white solid separated and was isolated by filtration and washed with Et0 (yield, 23.32 g). A mixture of this material in hot MeCN (300 mL) was treated with hot HzO (ca. 150 mL) until most of the solid dissolved. The hot misture wae filtered, and the fiitrate wae kept overnight at rt. Compound 4 separated as a colorless crystalline solid and was isolated by fiitration. The fiitrate, upon evaporation to a volume of about 50 mL, gave a second fraction of produd: combined yield, 21.98 g (93%);mp 144-146 OC dec; 1H NMR (DMSO-dd b 2.46 (s,3 H), 7.55-7.74 (aromm's; lines at 7.57,7.60,7.70,7.72; 3 H), 10.06 (br s, 1H); 1SC NMR (DMSOde) 6 20.1, 109.6, 125.8, 128.5, 134.3, 141.2, 141.9. Anal. Calcd for C7H7IO& C, 26.77; H, 2.25. Found: C, 26.93; H, 2.32. 1H-1-(l-Hexynyl)-5-methyl-l~~benziodoxathiole 3f-Dioxide (5b, R = n-Bu). A mixture of 4 (1.57 g, 5.00 mmol), TsOH-H~O(0.95 g, 5.0 mmol), and 1-hexyne(2.05 g, 25.0 mmol) in MeCN (40 mL) was stirred and heated under reflux for 20 h; the resulting solution was concentrated (rotary evaporator) to an oil. A solution of the oil in CHCb (200 mL) was washed with 5% NaHC03 (80mL) and HzO (3 X 50 mL) and concentrated to a solid (1.57 9). Recrystallization of this material from a mixture of CH2C12 (30 mL), EhO (ca. 100 mL), and hexanes (ca. 60 mL) gave 5b ae an off-white solid yield, 1.02 g (54%); mp 179-181 OC dec; IR 2164 cm-l ( C e ) ; lH NMR (CDC1.d 6 0.93 (t,J = 7.3 Hz, 3 H), 1.45 (m, 2 H), 1.64 (m, 2 H), 2.46 (8, 3 H), 2.69 (t, 7.1 Hz, 2 H), 7.44 (dd, 1H), 7.89 (d, 8.7 Hz, 1H), 7.96 (d, 1H); 1% NMR (CDCb) b 13.4,20.5,20.7,21.9(5), 28.2,29.8, 105.6, 115.4, 126.8, 130.6, 135.0, 141.5, 143.6. Anal. Calcd for Cl&IidOaS C, 41.28; H, 4.00. Found C, 41.47; H, 4.01. 1H-1- (1-Pentyny 1)-5-methy 1-1,2,3-ben ziodoxathiole 3,3Dioxide (58, R = n-Pr): from 4 (2.20 g, 7.00 mmol), TsOHeH20 (1.33 g, 7.00 mmol), 1-pentyne (2.38 g, 34.9 mmol), and MeCN (50 mL); 17 h, reflux; aqueous workup; crude solid (2.00 g) recrystallized from CH&lz (40 mL) with EhO and again from CH2Cl2 (30 mL) and EhO (ca. 100 mL) to give Sa as a yellowish solid yield, 1.55 g (61%); mp 159-161 "C dec; IR 2168 cm-l ( C e ) ; 'H NMR (CDCb) & 1.06 (t, 7.4 Hz,3 H),1.71 (m, 2 H), 2.48 (a, 3 H), 2.68 (t,7.1 Hz, 2 H), 7.46 (ddd, 1H), 7.89 (d, 1H), 8.00 (dd, 1H); W NMR (CDCb) 6 13.5,20.7,21.4(5), 22.7,28.4, 105.6, 115.2, 126.9, 130.6, 135.0, 141.5, 143.6. Anal. Calcd for C12Hi&S C, 39.57; H, 3.60. Found C, 39.66; H, 3.60. 1H-l-(l-Heptynyl)-5-methyl-l,2,3-benzi0do~athiole 3,3Dioxide (5c,R = m-C&): from4(1.26g,4.01mmol),TsOH.HzO (0.76 g, 4.0 mmol), 1-heptyne (1.15 g, 12.0 mmol), and MeCN (40 mL); 20.5 h, reflux; aqueous workup; crude solid (1.12 g) recrystallized from CH2Clr (20 mL), Et0 (ca. 100 mL), and hexanes (ca. 50 mL) to give 5c as a pale-yellow solid yield, 0.65 g (41%); mp 170-172 OC dec; IR 2163 cm-1 (M); 1H NMR
-
Notes 1H-1-(1-Octynyl)-&methyl-l~f-ben~odo~thiole 3,3-Dioxide (5d, R = n-C'H18): from 4 (1.57 g, 5.00 mmol), TsOH.H& (0.95 g, 5.0 mmol), 1-odyne (2.75 g, 25.0 "011, and MeCN (40 mL); 14 h, reflux; aqueous workup; crude solid (1.69 g) recryeW e d from CHzCl2 (50 mL), EhO (ca. 200 mL), hexanes (ca. 150 mL) to give 5d as a pale yellow solid yield, 1.04 g (51%); lH NMR (CDCb) 6 mp 152-154 OC dec; IR 2167 cm-I (-1; 0.88 ('t", 3 H), 1.2-1.5 (closely spaced m's at 6 1.30, 1.42,6 HI, 1.65 (m, 2 H), 2.46(5) (e, 3 H), 2.68 (t, 7.1 Hz, 2 H), 7.43 (dd, 1 H), 7.89 (d, 1 H), 7.97 (d, 1H); '42 NMR (CDCb) 6 14.0, 20.7, 20.8, 22.4, 27.8, 28.3, 28.5,31.1, 105.6, 115.4, 126.8, 130.6, 134.9, 141.5, 143.6. Anal. Calcd for CISHISIOSS C, 44.34; H, 4.71. Found C, 44.34; H, 4.61. LH-l-(dMethyl-l-pentynyl)-bmethyl-l~ben~odo.athiole 3,g-Dioxide (Se, R = i-Bu): from 4 (1.57 g, 5.00 mmol), TsOH.H20 (0.95 g, 5.0 mmol), Cmethyl-1-pentyne (2.05 g, 25.0 mmol), and MeCN (40 mL); 23 h, reflux; aqueous workup; crude solid (1.58 g) recrystallized from CH2Cl2 (30 mL) and Et0 (ca. 100mL) to give 5e as a tan solid yield, 1.25 g (66 % ); mp 193-195 OC dec; IR 2164 cm-1 ( ( 2 4 ) ; 1H NMR (CDCb) 6 1.04 (d, 6.65 Hz,6 H), 1.98 (septet, 6.6 Hz, 1H), 2.46 (s,3 H), 2.59 (d, 6.5 Hz,
2H),7.44(dd,1H),7.90(d,1H),7.96(d,1H);1WNMR(CDCb) 6 20.7, 22.0, 27.9, 28.9, 29.8, 105.7, 114.4, 126.8(5), 130.6, 135.0, 141.5, 143.6. Anal. Calcd for ClJ-IldOsS: C, 41.28; H, 4.00. Found: C, 41.02; H, 3.95. lH-1-(%Methyl-1-pentyny 1)-&methyl-1,2 3-benziodoxathiole 3,t-Dioxide (at, R = eBu): from 4 (1.57 g, 5.00 mmol), TsOH.HzO (0.95 g, 5.0 mmol), 3-methyl-1-pentyne(1.02 g, 12.4 mmol), and MeCN (40 mL);23 h, reflux; aqueous workup; crude solid (0.94 g) recrystallized from CHzCl2 (20 mL), Et0 (ca. 100 mL) to give 5f as a pale-yellow solid yield, 0.61 g (32%); mp 159-161 OC dec; IR 2154 cm-1 (W); lH N M R (CDCb) 6 1.03(5) (t, 7.4 Hz, 3 H), 1.30 (d, 7.0 Hz, 3 H), 1.61 (quintet, 2 H), 2.46 (e, 3 H), 2.85 (m, 1H), 7.45 (ad, 1H), 7.88 (d, 1H), 7.97 (d, 1H); '3C NMR (CDCls) S 11.6(5), 19.8, 20.7, 28.5, 29.2, 29.8, 105.7, 119.4,126.6,130.6,135.0, 141.5, 143.6. Anal. Calcd for C16IlaIO& C, 41.28; H, 4.00. Found C, 41.30, H, 4.05.
1H-l-(3,3-Dimethyl-l-butynyl)-5-methyl-1,2,3-benziodoxathiole3,3-Dioride (5g,R = t-Bu):from 4 (1.26g, 4.01 mmol), TsOH.H20 (0.76 g, 4.0 mmol), 3,3-dimethyl-l-butyne (1.64 g, 20.0 mmol), and MeCN (30 mL); 16.5 h, reflux; aqueous workup; crude solid (1.25 g) recrystallized from CHaClz (20 mL) and Et.& (ca. 60 mL) to give 5 g as a white solid yield, 1.06 g (70%1; mp lH NMR (CDCb) 6 1.36 212-214 OC; IR 2135,2173 cm-I (W); (e, 9 H), 2.46 (s,3 H), 7.46 (dd, 1H), 7.83 (d, 1 H), 7.97 (d, 1H);
'SCNMR(CDCl~)S20.7,27.6,30.1,30.2,105.6,122.7,126.4,130.6, 135.0, 141.5, 143.5. Anal. Calcd for Cl&IOaS: C, 41.28; H, 4.00. Found C, 41.12; H, 3.98. lH-1-(Cyclohexylethynyl)-5-methyl-l,2f-benzidoxathiole3,3-Dioxide (5h,R = cyclohexyl):from4 (1.57g,5.00mmol), TsOH-HzO (0.95 g, 5.0 mmol), cyclohexylacetylene (0.95 g, 8.8 mmol), end MeCN (40mL); 16h, reflux; aqueousworkup; residual material treated with warm EhO (20 mL) to give crude solid (0.82 9); solid recrystallized from CH2C12 (3C mL) and EhO (ca. 150mL)togive5hasatansolid yield,0.52g(26%);mp199-201 OC dec; IR 2155 cm-1 (W); 1H NMR (CDCb) 6 1.25-2.00 (four closely spaced, poorly resolved m's, 10 H), 2.46 (8, 3 H), 2.86 (m, 1H), 7.45 (dd, 1H), 7.88 (d, 1H), 7.97 (d, 1HI;*BcNMR (CDCb) 6 20.7,24.6,25.3,28.3,31.1,31.8,105.7,119.1,126.6,130.6,135.0, 141.5,143.5(5). Anal. Calcd for ClSH17IOaS: C, 44.56; H, 4.24. Found C, 44.34; H, 4.18. lH-l-(Phenylethynyl)-&methyl-l~~-hendodolathiole S,3Dioxide (Si, R = Ph): from 4 (1.26 g, 4.01 mmol), TsOH-HnO (0.76g,4.0mmol),phenylacetylene (2.04g, 20.0mmol),andM&N (40 mL); 7 h, reflux (product separated from solvent); reaction mixture treated with EBO (10 mL), kept in an ice bath for 2 h, and fiitered to give 51 as a white solid (washed with EhO,dried in air): yield, 0.81 g (51%);mp 221-223 "C dec; IR 2154 cm-' 'H NMR ( D M S O 4 & 2.43(5) (s,3 H), 7.5-7.66 (m, 4 H), (CDCb)S0.89('tn,7.1Hz,3H),1.36(m,4H),1.65(m,2H),2.46 (M); (~,3H),2.68'(t,7.2Hz,2H),7.43(ddd,lH),7.89(d,2H),7.95(5) 7.73-7.81 (m, 3 H), 8.10 (d, 8.5 Hz, 1H); 'SC NMR (DMSO-&) 6 20.2, 41.3, 107.2, 107.7, 119.4, 128.8(5), 129.09, 129.14, 131.6, (dd, 1H); 1% NMR (CDCb) 6 13.8, 20.7, 20.8, 22.0, 27.5, 28.2, 133.0,135.0,142.4,142.6.Anal. Calcd for Cl&IOaS C, 46.24; 30.9, 105.6, 115.4, 126.9,130.5, 134.9, 141.5, 143.5. Anal. Calcd H, 2.78. Found C, 45.12; H, 2.80. for C&1710& C, 42.87; H, 4.37. Found C, 42.56; H, 4.36.
